Device for preventing carburetor flooding



Oct. l1, 1966 P. S. ROSENBERG DEVICE FOR PREVENTING CARBURETOR FLOODING Filed Sep'l'.. l0, 1954 1N VENTOR.

United States Patent O 3,277,877 DEVICE FOR PREVENTING CARBURETOR FLOODING Pinkus S. Rosenberg, Indianapolis, Ind., assignor to Indanapolis Manufacturing Corporation, Indianapolis, Ind., a corporation of Indiana Filed Sept. 10, 1964, Ser. No. 395,482 4 Claims. (Cl. 123--136) The present invention relates to a device for preventing carburetor flooding in internal combustion engines, and consists essentially of means which will act, when such an engine is stopped, affirmatively to withdraw fuel in a predetermined quantity from the bowl of the engine carburetor; and then, when the engine is restarted, to return the fuel so Withdrawn to the carburetor bowl.

In present-day automobile power systems, the fuel is fed by means of a pump, or some other suitable apparatus, under pressure to the carburetor. Its flow into the carburetor is controlled by a float actuated needle valve. Such a pump furnishes fuel at a significant superatmospheric pressure; and when the engine is stopped, the fuel which is under pressure in the line between the pump and the carburetor will, in many instances, leak slowly past the needle valve into the carburetor, thereby overfilling, and sometimes overflowing, the carburetor bowl to allow raw fuel to flow into the intake manifold. This will result, eventually, in crankcase oil dilution, which will often render the engine hard to start, and will result in a slight increase in fuel consumption.

In order to overcome these diiliculties, it is the primary object of the present invention to provide a device which will act automatically, whenever the engine stops, to withdraw a quantity of liquid fuel from the carburetor bowl, thereby lowering the level of fuel in the bowl and providing a space within which fuel, leaking past the needle valve as above suggested, may accumulate, without overflowing into the intake manifold. According to the present invention, such withdrawn fuel is retained in a reservoir and will be returned to the carburetor as soon as the engine is restarted.

Further objects of the invention will appear as the description proceeds.

To the accomplishment of the above and related objects, my invention may be embodied in the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific constructions illustrated and described, so long as the scope of the appended claims is not violated.

FIG. 1 is a somewhat diagrammatic illustration of a conventional internal combustion engine, including a fuel pump, an oil pump and a carburetor, with an embodiment of my invention operatively associated therewith;

FIG. 2 is an enlarged, axial section through the device illustrated in FIG. l; and

FIG. 3 is a similar section, but showing an .alternative form of operating means therefor.

Referring more particularly to the form of invention illustrated in FIGS. l and 2, `my flooding preventer is indicated generally by the reference numeral and is shown in operative association with the carburetor 11 of an internal combustion engine 12. The device, as shown, comprises a housing made up of two mating parts 14 and 15 joined together at their peripheries by suitable fastening means such as the bolts 16 and clamping therebetween the Iperiphery of a flexible, liquid-impervious diaphragm 17. It will be apparent that said diaphragm spans the interior of the housing and divides the same into inversely-variable-volume chambers 18 and 19.

A rigid seat plate 20 is secured to one surface of the diaphragm 17 within the chamber 18, and a coiled, pref- 3,277,377 Patented 0st. l1, 1966 ICC erably spiral expansion spring 21 is confined between said seat plate and the facing wall of the housing part 14. That wall is centrally formed with an internally threaded port 22, disposed on an axis perpendicular to the plane of the plate 20, and adapted threadedly to receive a fitting 23 whereby one end of a conduit 24 may be supported in open communication with the chamber 18. The other end of said conduit 24 is suitably connected, as at 25, to the carburetor 11 in open communication with the interior of the bowl of said carburetor at a suitable level. As shown, and preferably, the conduit 24 may be a rubberoid hose or other flexible conduit means. Thus the interior of the carburetor bowl is placed in open communication with the interior of the reservoir chamber 18.

A second rigid seat plate 26, preferably having an outturned, peripheral lip 27, is fixed to the opposite surface of the diaphragm 17 within the chamber 19. As shown, and preferably, the plates 20 and 26 will be secured to the diaphragm 17 by means of rivets 28 penetrating both plates and the diaphragm.

The housing part 15 is formed with an internally threaded port 29 which is in perpendicular registry with the seat plate 26 and which is designed threadedly to receive la threaded fitting 30. The other end of the fitting 30 is designed for attachment thereto of one end of a conduit 31 through any suitable means such as, for instance, the nut 32. The opposite end of the conduit 31 is suitably connected to the outlet port of the conventional oil pump 33 which is a part of the oil-circulating system of the engine.

When the engine is in operation, fuel will be supplied, by the conventional pump 34, to the carburetor 11. At the same time, the oil pump 33 will deliver oil, under a predetermined pressure, through the conduit 31 to the chamber 19; and the spring 21 is so calibrated that it will be overpowered by the pressure of oil in the chamber 19, whereby the diaphragm 17 will be held in the dotted line position of FIG. 2. When, however, the engine is stopped, the pressure in the chamber 19 will be abated, and the spring 21 will move the diaphragm to the solid line position of FIG. 2. As the otherwise-closed, variable-volume reservoir 18 is thus expanded or enlarged, it will tend to create a vacuum in the conduit 24, whereby liquid fuel in the carburetor bowl will be withdrawn into the reservoir 18, thus lowering the level of such liquid fuel in the carburetor bowl to the selected level of the port 2S. The size of the reservoir 18, when so expanded, is so selected as to guard against any possibility that fuel, leaking past the needle valve, can rise high enough in the bowl to overflow into the intake manifold.

When, now, the engine is restarted, pressure will again be built in the chamber 19 to overpower the spring 21, thus moving the diaphragm 17 to the dotted line position of FIG. 2 and returning the fuel from the chamber 18 to the bowl of the carburetor 11.

Alternatively, other means may be adopted for automatically controlling the position of the diaphragm 17. As shown in FIG. 3, a solenoid 35 may be provided, having an externally threaded spud 36 in which is reciprocably mounted an armature 37 which is projectible upon energization of the solenoid. The spud 36 is proportioned and designed for threaded mounting in the port 29, and the armature 37 is so constructed that, when said spud is so received and the solenoid is not energized, the force of the spring 21 will move or hold the armature 37 to the position illustrated in FIG. 3. Upon energization of the solenoid 35, however, the armature 37 will be projected, overpowering the spring 21, to shift the diaphragm 17 to the dotted line position of FIG. 2.

Manual means will be provided for controlling the energizing circuit for the solenoid 3S; and I presently prefer that the lead 38 for such circuit shall extend through the conventional ignition switch 39, usually operated by a key 40. Thus, when the ignition switch is closed, the solenoid will be energized to shift the diaphragm 17 to discharge fuel from the reservoir 18 to the carburetor bowl and the diaphragm will be held in that position until the switch 39 is reopened, whereupon the spring 21 will return the diaphragm 17 to its solid line position to withdraw excess fuel from the carburetor bowl.

I claim as my invention:

1. In combination with the carburetor of an internal combustion engine, a closed, variable-volume reservoir having a movable wall, spring means acting on said wall yieldably to resist reservoircontracting movement of said Wall, a solenoid having an armature cooperatively engageable with said wall to overpower said spring means upon energization of said solenoid, a manually-controllable energizing circuit for said solenoid, and conduit means providing open communication between the interior of said reservoir and the bowl of said carburetor.

2. In combination with the carburetor of an internal combustion engine, a closed, variable-volume reservoir having a movable wall, spring means acting on said wall yieldably to resist reservoir-contracting move'ment of said wall, a solenoid having an armature cooperatively engageable with said wall to overpower said spring means upon energization of said solenoid, an energizing circuit for said solenoid including the ignition switch for said engine, and conduit means providing open communication between the interior of said reservoir and the bowl of said carburetor.

3. In combination with the carburetor of an internal combustion engine, a housing having a first stationary wall and a second stationary Wall, a movable wall within said housing defining, with said rst wall, a variable-volume reservoir and defining, with said second Wall, an inversely-variablevolume chamber, spring means yieldably biasing said movable wall in a direction to enlarge said reservoir, said first Wall being formed with a first port opening into said reservoir, conduit means connecting the bowl of said carburetor with said first port, said second Wall being formed with a second port opening into said chamber, a solenoid having an armature, means for mounting said solenoid on said second wall with said armature entering said chamber through said second port, said armature acting upon said movable wall, upon energization of said solenoid, to overpower said spring means, and a manually-controllable energizing circuit for said solenoid.

4. In combination with the carburetor of an internal combustion engine, a housing having a first stationary wall and a second stationary wall, a movable wall within said housing defining, with said first Wall, a variable-volume reservoir and defining, with said second wall, an inversely-variable-volume chamber, spring means yieldably biasing said movable wall in -a direction to enlarge said reservoir, said first Wall being formed with a first port opening into said reservoir, conduit means connecting the bowl of said carburetor with said first port, said second wall being formed with a second port opening into said chamber, a solenoid having an armature, means for mounting said solenoid on said second wall with said armature entering said chamber through said second port, said armature acting upon said movable wall, upon energization of said solenoid, to overpower said spring means, and an energizing circuit for said solenoid including the ignition switch for said engine.

References Cited by the Examiner UNITED STATES PATENTS 2,578,730 12/1951 Nicholson et al. 92-100 2,685,919 8/1954 Plass et al. 158-36 2,986,133 5/1961 Mattson 12.3-136 3,148,671 9/1964 Bottorff et al. 123-136 X MARK NEWMAN, Primary Examiner. L. M. GOODRIDGE, Assistant Examiner. 

1. IN COMBINATION WITH THE CARBURETOR OF AN INTERNAL COMBUSTION ENGINE, A CLOSED, VARIABLE-VOLUME RESERVOIR HAVING A MOVABLE WALL, SPRING MEANS ACTING ON SAID WALL YIELDABLY TO RESIST RESERVOIR-CONTRACTING MOVEMENT OF SAID WALL, A SOLENOID HAVING AN ARMATURE COOPERATIVELY ENGAGEABLE WITH SAID WALL TO OVERPOWER SAID SPRING MEANS UPON ENERGIZATION OF SAID SOLENOID, A MANUALLY-CONTROLLABLE ENERGIZING CIRCUIT FOR SAID SOLENOID, AND CONDUIT MEANS PROVIDING OPEN COMMUNICATION BETWEEN THE INTERIOR OF SAID RESERVOIR AND THE BOWL OF SAID CARBURETOR. 